Circuit boards or "cards" are an accepted means for installing auxiliary or supplemental interchangeable circuitry in computers and electronic equipment of all kinds--found in automobiles, appliances, etc. The boards themselves are undergoing continual changes, such as conversion to surface mounting of components, but in general have become so well accepted as to escape some desirable critical review.
Usual substrate material for circuit boards or the like is non-conductive and in the form of self-supporting sheets to carry conductive structures plated or otherwise deposited thereon, as in a thin film, or inserted into bores or openings molded or otherwise formed therein, or secured thereto in some acceptable manner. Conductive structures on one or both faces thereof may be connected to one another by conductive traces along a face or via bores from one face through to the opposite face plus appropriate terminals, leads, etc. Resulting circuit boards and their component substrates usually are made up of smooth-surfaced polymeric thermoplastic sheet material with a thickness on the order of a millimeter or so, with or without a fibrous filler reinforcement, and capable of being flexed a bit.
Even "substrate-less" circuit boards disclosed in the present inventor's aforementioned patent, require physical support during their formative stages--removable at a later stage in the process. It would be advantageous if temporary support could be incorporated into the resultant structure while retaining benefits of substantial face-to-face homogeneity of side-by-side non-conductive and conductive compositions in a patterned electrical structural lamina.